Michael Jackson once said that if everyone in Hollywood who had undergone plastic surgery went on vacation, there would be no one left in town. As it is, even some of the most famous cinematic faces are becoming harder to recognise. First Renee Zellweger stunned fans globally at an awards ceremony in California last October when she turned up on the red carpet looking so radically different that the assumption was that she must have had surgery (chin implants and lid lifts were variously suggested). She was beautiful still but disturbingly unfamiliar. And now Uma Thurman has been photographed while promoting her new NBC mini-series, The Slap, premiering a face that has also launched a thousand speculative comments.
In the pictures, her familiar broad-browed, prominent cheek-boned and frankly majestic face that so perfectly complemented the mesmerising pale blue eyes appeared to have shrunk into a reverse Isosceles triangle. Those eyes now seem slanted, in almost direct contrast to Renee's - whose naturally Slavic eyes have been left, allegedly by cosmetic tweakery, resembling large marbles.
Whether they have been under the knife or not, both women still look amazing. And they are, of course, entitled to do anything they may want to their faces. But they have unwittingly become the poster girls for what seems to be a new development in cosmetic know-how, an essentially sculpted style that leaves women looking, well, not like themselves. And this in a town that has long considered women's physiognomy a moveable feast.
Yet they're not alone. Look past Renee and Uma, and there's Courteney Cox, who seems to have acquired a more exaggerated and wider cheek bone. Here's Catherine Zeta Jones, who looks - side on - as though someone has popped a spare breast implant under each cheek. Scarlett Johansson, at a youthful 30, has even laid down a marker, saying: ''I definitely believe in plastic surgery. I don't want to be an old hag. There's no fun in that.''
Crucially it doesn't seem enough to look ''refreshed'' any more. Practitioners of the new approach seem to be adopting a design ethic that knows no aesthetic limits.
So what's driving the women on? One Hollywood insider tells me that women are on a desperate trajectory: ''Two things are forever on the rise out here: cosmetic science and female insecurity. Merge the two and you get the perfect storm we're now witnessing, where stars seem to want to look like anyone but themselves - and are succeeding. The casting couch long ago went the way of multi-million dollar lawsuits, but in its place is a far more insidious thing: female actresses are being urged - either directly or covertly - to compete with younger women in the looks stakes, or they will be replaced,'' she says. ''Cue the desperate measures we are bearing witness to. Out here your looks, after all, are your fortune. And in this age of HD TV, women will do whatever it takes to stay in the game.''
She's echoing the words of fiftysomething Kim Cattrall (the sexually voracious Samantha in Sex and the City), who has said: ''You have to be desirable. And that's why so many woman of my age or even younger are pushed to Botox and plastic surgery, all the things that make people ask 'Why do women do this?' But where do you go in your fifties in your career?''
Certainly, Tinseltown is no stranger to visage-shifting stars. One of the first was Carole Lombard who, in 1926, had surgery to reduce the appearance of a facial scar. In 1958, medical records show that Marilyn Monroe consulted a doctor about her "chin deformity'', work that was apparently confirmed by the release this week of one of Monroe's first shoots, from 1946, which show a cheery-faced adolescent, with a well-rounded jawline instead of the more familiar heart-shape of legend.
Indeed, during the Golden Age of Hollywood, when a starlet could be ordered to change her name or background, physical appearance was hardly sacrosanct. Margarita Carmen Cansino turned into Rita Hayworth by using electrolysis to raise her hairline an inch. Both Monroe and Elizabeth Taylor are reported to have shaved their faces to produce a downy growth that gave them more of a glow under the cameras. Marlene Dietrich twisted back strands of hair using clips to lift her face and is also said to have had her back molars removed to improve the line of her cheekbones.
Once full facelifts were considered safe in the Seventies and Eighties, actors popularised what is sometimes called the American Widow or Wind Tunnel look - skin stretched back over skeletal cheekbones, as sported by Nancy Reagan and Joan Rivers in later life. A temptation for repeat lifts resulted in the "melted candle" faces epitomised by Mickey Rourke, whose appearance in The Wrestler, in 2008, bore no resemblance at all to that of his sexy John Gray in 91/2 Weeks from 1986. No wonder US commentator Ben Shapiro said that Beverly Hills looks like a moving Madame Tussauds.
Surgical techniques improved over time but were still not without risk. A friend recalls, back in the Nineties, visiting Michaeljohn, the London hair and beauty salon beloved of visiting US stars and hearing about one A-lister who had just left. This noted beauty - whose taste for ''work'' was no secret (she was said to worry about losing her younger, universally desired husband) - had apparently fallen asleep during a facial, and started snoring. It wouldn't have been so concerning for the therapist had not the eyes of said actress remained open throughout. Surgery - it seemed - had left her unable to operate fully her eyelids.
More sophisticated half-lifts, brow lifts and chin implants were followed by chemical peels, Botox and fillers, and a fashion for smoother, plumper younger-looking "pillow" faces. Twenty years on, and the results of surgery are ever more reliable, according to Kevin Hancock, consultant plastic surgeon and council member of the British Association of Aesthetic Plastic Surgeons. And as a result it's not just people in the public eye but the public who are becoming more knowledgeable and enthusiastic.
''Ordinary people want things done that don't look glaringly obvious; that make them look fresher and well, but not 'done'. They've been influenced by the explosion in the non-surgical market in the past 10 years - the Botox and fillers and peels, which, done well and done regularly, produce very nice results,'' he says.
Consultant plastic surgeon Peter Cumbo, of the Harley Street Skin Clinic, who offers what he calls a ''minimally invasive'' French lift, with hidden scarring, agrees. ''These days, we can work wonders by skilful use of Botox and fillers to lift, nip and tuck in a much gentler, and more natural way.'' He speculates that Uma Thurman may have gone down this route with skin resurfacing but no eye surgery, as some claim.
What is definitely changing in terms of shape and style - and possibly accounts for this new batch of sculpted Hollywood face shapes - is that clinicians have become much better at ''volumetric face lifting'', says Mr Hancock. ''In the old days we pulled skin tight, and that was that, but now we look at restoring volume as well. This can be done using artificial fillers, but is more likely to be created via fat injections, using the client's own tissue from somewhere like the tummy.''
The technique is popular as it uses natural material, which the patient's immune system is unlikely to reject, and tends to stay put permanently. Madonna is alleged to be one high-profile enthusiast.
With awareness comes a new attitude. ''There is much less social stigma attached to facelifts now," says Mr Hancock. "People are less concerned that others know they've had work done.''
Perhaps this also explains the confidence of our Hollywood heroines in debuting their new looks. But what's the betting they would still rather have joined that elite corps who seem to have achieved the enviable task of looking superb but in the have-they, haven't-they way, which must be the Holy Grail of cosmetic surgery. These are (allegedly) Dames Helen (69) and Judi (80), La Streep (65) and even Jane Fonda (77).
However, not everyone in Hollywood accepts that cosmetic makeovers are the price of enduring fame. Recently, the Australian actor Guy Pearce said of those who opt for it: "We look at them and go 'I can tell you've had plastic surgery. You look really strange to me'. But no one's saying anything. We're just accepting the fact that they're strange-looking.''
Strange but beautiful, none the less.